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March 6 is not a good day to buy a new car. In fact, if you’re hoping to get a decent price at the dealership—and who isn’t?—this Tuesday is supposedly the worst day of the month, and one of the worst days of the entire year, to go car shopping. But it’s not the year’s worst day.

That dubious honor goes to Tuesday, April 10, 2012, when the average buyer will get a measly 5.1% off of the sticker price. Toward the end of December, by contrast, vehicles will typically sell at 8.5% to 9.5% below MSRP. That’s a big difference compared to 5.1%, or to 6.0%, which is the average discount off MSRP for cars selling on Tuesday, March 6.

According to TrueCar’s recent estimates, the best time to buy recently was Saturday, February 25. The worst day? Tuesday, March 6. That is, until Tuesday, April 10 rolls around.

If you’re noticing a pattern, it’s because there is one. As you’ve probably heard, dealerships are far more game to haggle and let cars go for lower prices toward the end of the month. This isn’t just rumor and speculation; the numbers really back this theory up.

TrueCar senior analyst Kristen Andersson explains, “The last third of the month is typically when a dealer can tell how the month is going and can incentivize the vehicles.” The beginning of the month, she says, is typically slow, and “they don’t want to give the product away.”

Well, no wonder sales are slow at the start of the month: That’s when prices are highest. It really doesn’t matter whether sales are slow because prices are high, or prices are high because sales are slow. At this point, both sides of the equation probably combine to form a self-perpetuating trend. What matters to consumers is that it’s unwise to buy during this slow-sale, high-price period.

As for particular days of the week, Mondays and Tuesdays are to be avoided, and especially Mondays and Tuesdays early in the month. Why’s this? Because dealerships view consumers who come in on Mondays and Tuesdays as “need-based buyers,” according to Andersson, and these buyers “don’t negotiate as much as the savvy weekend shoppers who do their homework.”

There are exceptions, of course. A holiday weekend Monday that falls toward the beginning of the month, for instance, can be a good time to buy. And some years, TrueCar estimates that the worst day to buy in the entire calendar is not a Monday or Tuesday but a Sunday. Specifically: Easter Sunday.

The assumption is that anyone shopping for a car on Easter Sunday must be a “need-based buyer.” Come Easter, you could try to explain to a car salesman that such a description doesn’t apply to you—that you’re a savvy buyer who knows what price you want, and that you’re shopping on Easter because you just want to avoid the crowds.

But car salesmen aren’t known to be easily dissuaded from their preconceptions. It’s probably smarter just to stick around longer at the Easter egg hunt, and go shopping for a car at the end of the month.

Brad Tuttle is a reporter at TIME. Find him on Twitter at @bradrtuttle. You can also continue the discussion on TIME’s Facebook page and on Twitter at @TIME.